Green-roof guru delivers the gospel

With the city of Louisville moving forward with its first "green roof," Mayor Jerry Abramson welcomed one of the movement's leading experts last night.

Trying to inspire, Ed Snodgrass of Emory Knoll Farms in Maryland took more than 100 local architects, developers and other invited guests on a photographic tour of green roofs around the world.

Many were in Europe, but others were in American cities, including Baltimore and Evansville, Ind.

People are using grasses, succulents, wildflowers and other plants to top corporate headquarters, city halls, warehouses, office buildings and houses. In doing so, Snodgrass said, they have helped cool their surroundings, reduce air pollution, attract birds and butterflies and soak up storm water that otherwise would get dirty and foul streams or lakes.

A three-inch-thick green roof can capture 50 to 70 percent of the rainfall, he said.

But he said government needs to lead. "It's not going to happen without some incentives."

Emory Knoll Farms has supplied plants to 286 rooftop projects, greening an estimated 2 million square feet of what otherwise would be black tar or shingles.

Those conventional, dark-colored roofs can produce temperatures of 180 degrees in the summer, he said.

"I have this delusion, or highly optimistic wish, that (United Parcel Service) and all those warehouses you see flying into Louisville" will have green roofs someday, said Gill Holland .

Holland and his wife, Augusta , co-sponsored the event with the Kentucky Chapter of the American Society of Landscape Architects and metro government.

The couple are putting a green roof on a century-old warehouse they are renovating on East Market Street.

In August, metro government took its first step to install a green roof, requesting proposals to retrofit the 14,000 square feet of tar and gravel atop the 444 Building, at 444 Fifth St., which houses the Metro Development Center.

Abramson spokesman Chris Poynter said the city has awarded a $35,000 contract to the firm Luckett & Farley to design the green roof.

Construction could begin in the spring, Poynter said.

The Brown-Forman Corp. also has a small green roof on one portion of its Louisville headquarters.

But Louisville is behind some other cities, such as Chicago, which boasts more than 250 green roofs.

While Snodgrass said green roofs can be more expensive, they can last up to 50 years. He acknowledged that there can be difficulties.

While in the Louisville area, for example, Snodgrass visited Bernheim Arboretum and Research Forest, which has problems with its green roof atop a new visitor center.

Snodgrass said he thinks a construction flaw that doesn't seem to allow for proper drainage might help explain why some of the plants on the roof have died.

But some also dried up because of heat and drought, said Harold Hendricks , operations manager at Bernheim. Weeds also invaded, he said.

"We tried not to water," Hendricks said, explaining that forest officials were trying to conserve. "It's kind of a learning curve."